There are several formats used for storing waveform data within a computer system. OS/2 multimedia recognizes several resolutions of the Pulse Code Modulation (PCM) format, because it is supported by most audio adapters. OS/2 multimedia also recognizes ADPCM formats. Refer to the Appendix of the OS/2 Multimedia Programming Reference for descriptions of these formats.
Pulse Code Modulation (PCM) refers to the variation of a digital signal to represent audio amplitude. This method of assigning binary values to amplitude levels supports the conversion of analog signals to digital signals by adapters such as the M-Audio Capture and Playback Adapter.
Adaptive Differential Pulse Code Modulation (ADPCM) is a technique for compressing waveform samples. ADPCM can reduce the amount of data storage required by a factor of 16 to 1, but some price is paid in fidelity for the higher compression rates.